Enzymatic Management of pH in White Wines

This paper investigates the potential of the enzymatic management of high pH in white juice and wine using a combination of enzymes-glucose oxidase coupled with catalase. Catazyme^® 25 L, a commercially available blend of the two enzymes, was added at different doses (0.2 g/L, 0.6 g/L, and 1g/L) to white grape juice and various parameters (glucose, gluconic acid, pH) were monitored over 24 h of treatment. Treated wines were fermented to dryness without any difficulty and the wines were chemically and sensorially evaluated. At the highest dose (1 g/L), pH was reduced from 3.9 to 3.2, with 20.5 g of gluconic acid produced, while at the lowest dose (0.2 g/L), pH decreased from 4.0 to 3.5 and 8.8 g of gluconic acid was produced. Flash profiling indicated that treated wines were lighter in color than the control and were described using terms such as floral, fruit, citrus, and sour while the control wine was described as being fermented, medicinal, pungent, and oxidized. In conclusion, glucose oxidase coupled with catalase was shown to be effective at significantly reducing juice and wine pH in a short amount of time and with a positive impact on the organoleptic profiles of the treated wines.